Valve adjusting mechanism



A118. 16, 1932- R. R. HUTCHISON 7 VALVE ADJUSTING MECHANISM Filed Aug. 13, 1927 Patented Aug. 16, 1932 UNITED STATES PATENT OFFICE ROBERT E. HUTCHISON, OF PONTIAC, MICHIGAN, ASSIGNOR TO GENERAL MOTORS COR- PORATION, OI DETROIT, MICHIGAN, A CORPORATION OF DELAWARE VALVE ADJUSTING MECHANISM Application filed August 13, 1927. Serial no. 212,802.

valve lifter of the rocker type which makes direct contact with the end of the valve stem is used. But if it is necessary to position a push rod or tappet intermediate the end of the valve stem and the rocker-lifter to provide for lash adjustment, as is common, this saving in bulk can not be effected. If the push rod or tappet is eliminated, as is desirable to eflect the decrease in bulk of the block, it is necessary to position the lash adjustment means on either the valve stem or the rockerlifter. If the adjustment means is positioned on the valve stem it is rather inaccessible and three wrenches, at least one of which must be of special design, are necessary to eflect the adjustment. If the adjustment means is positioned on the rocker-lifter in the ordinary manner it is much more inaccessible than when on the valve stem. It is an object of the invention to provide a means of lash adjustment on the rocker-lifter which is easily accessible and for the operation of which only an ordinary screw-driver and wrench are necessary.

It is a further object of the invention to provide a new and improved rocker-lifter.

It is a further object of the invention to rovide a pivoted lifter which extends from 1ts point of contact with the lower end of the valve stem outwardly to a point adjacent an opening in the side of the engine and means in the outer end of the lifter and accessible through the opening whereby lash adjustment may be effected.

Other objects of the invention will be obvious from the following description of the preferred embodiment of my invention which is illustrated in the accompanying drawing.

In the drawing, there is shown a fragmentary cross section through a cylinder of an L-head engine.

Referring to the drawing, the reference character 1 indicates the cylinder block of an L-head engine, in which there are provided a plurality of cylinders 2 opening through the top of the block and a passage 3 extending from the ort 4 in the side of the lateral portion 5 of t e block to an opening 6 in the top thereof adjacent each cylinder. To the top of the block, there is secured the cylinder head 7 in the under side of which there is provided a recess 8 which provides a passage 9 between the block and the head from the opening 6 to the top of the cylinder. Within the cylinder, there is provided the usual piston 10 connected to the crankshaft by a. connecting rod 11.

The opening 6 is controlled by a poppet valve 12, which is seated on the upper edge thereof and has a stem 13 extending through the opening, through the guide sleeve 14 which is secured in the lateral portion 5 of the block, and into the compartment 15 below the lateral portion. A coiled spring 16, which is located in the compartment 15, and which surrounds the lower end of the valve stem and is seated at its u per in a recess 17 in the cylinder block an at its lower end on a washer 18 secured to the lower end of the valve stem, tends to keep the valve 12 on its seat and the opening 6 closed. An opening 19, which is closed by a removable cover 20, is provided in the side of the block to allow access to the compartment 15 and the lower ends of the valve stems.

The valve is actuated by a rocker type lifter 21, which includes a member 22 extending from a point beneath the valve stem 13 to a point adjacent and accessible through the opening 19. The member 22- is bored longitudinally providing a relatively large opening 23 adjacent its outer end and a smaller opening 24 coaxial with the opening 23 and extending from the inner end thereof to the inner end of the member 22. At the junction of the openings 23 and 24 is formed a shoulder 25. Adjacent its inner end, the member 22 is bored transversely providing an opening 26 extending from its lower s de upwardly, passing through the opening with its axis intersecting the axis thereof. and into an upwardly extending projection 27 located on the upper side of the member directly beneath the lower end of the valve stem 13. The upwardly extending projection 27 is provided with an opening 28 in its upper end concentric with and of smaller diameter than the opening 26 leaving an inwardly extending flange 29 at the upper end of the opening 26. \Vithin the opening 26 and having its upper end projecting through the opening 28 and adapted to contact with the lower end of the valve. stem is a pin 30. On the lower end of the pin, 30, there is provided a head 31 slidably contacting with the side wall of the opening and provided with an inclined lower surface 32 projecting into the open ing 24. Surrounding the pin 30 and bearing at its opposite ends on the flange 29 and the head 31 is a coiled spring 33 adapted to urge the'pin downwardly.

Arranged to slide in the longitudinal openig in the member 22 is a pin 34 having a beveled inner end 35 underlying the pin 30 with its beveled surface in contact with the inclined lower surface 32 of the head of the pin 30. Firm contact between the surfaces 32 and 35 is maintained by the spring 33. The pin 34 extends into the opening 23 and has adjacent its outer end a collar 36. A coiled spring 37 surrounds the pin 34 and bears at its opposite ends against the collar 36 and the shoulder 25 and urges the pin 34 outwardly. A screw 38 is threaded in the outer end of the opening 23 and contacts at its inner end with the outer end of the pin 34 to limit the outward movement of the latter. Firm contact between the pin 34 and the screw is maintained by the spring 37. The screw is provided with a lock nut 39 to secure it in any desired position.

Adjacent its outer end and on its upper side, the member 22 is provided with an 11pwardly extending lug 40 having therein an opening 41 in which is positioned a bushing 42. Extending through the bushing 42 is a shaft 43 extending longitudinally of the engine and providing a pivotal mounting for the lifter. Intermediate its ends and on its lower side, the member 22 is provided with cam-shaped lug 44 with which a cam 45 on the camshaft 46, which is connected with the crankshaft by a chain or other means, is adapted to contact to rock the lifter about its pivot 43.

Upon rotation of the crankshaft, the camshaft is rotated and the lift portion of the cam 45 comes into contact with the lug 44, causing the lifter 21 to rock about its pivot 43 and the pin 30 to come into contact with the lower end of the valve stem 13. Further rotation of the camshaft causes the valve stem to move vertically upward in the guide 14 and the valt e 12 to move off its seat which opens the passage 3 to the passage 8. Ohviously, there will be considerable Wear on the contacting surfaces of the valve stem and the pin 30. In order to have correct valve operation. it is necessary that the lower end of the valve stem be spaced slightly from the upper end of the pin 30 when the inner end of the rocker-lifter is in its lowermost position so that the valve will seat properly. In order to have quiet valve operation it is desirable that this space be as small as possible. In order to maintain the proper spacing, it is necessary at intervals to adjust the pin 30 to compensate for the wear between the surfaces. In order to raise the pin 30, it is necessary only to remove the cover 20, loosen the locknut 39 and screw the screw 38 inwardly the proper distance. The lock-nut will then be tightened to prevent any undesired movement of the screw. Inward movement of the screw 38, it will be noted, will force the pin 34 inwardly and the wedge action exerted by the beveled end 35 of the pin 34 on the inclined end 32 of the head of the pin 30 Will cause the latter pin to move upwardly a distance dependent on the distance the screw 38 is moved inwardly and the slope of the beveled surface 35.

If it is desired to increase the amount of clearance between the end of the valve stem and the pin 30, it is necessary only to loosen the locknut 39, unscrew the screw 38 the proper amount and then tighten the locknut to prevent any undesired movement of the screw. Upon outward movement of the screw 38, the spring 37 will expand and move the pin 34 outwardly an equal amount. Upon outward movement of the pin 34, the spring 26 will expand moving the pin 30 downwardly a distance dependent on the distance the pin 34 is moved outwardly and the slope of the inclined surface 35.

It is obvious from the preceding description that I have provided a means of lash adjustment which is easily accessible and for the operation of which only two common tools, a wrench and a screw-driver are necessary.

Though I have shown and described my invention as applied to an L-head engine, it is clearly not limited to such a restricted use but may be used in connection with any or all of the inlet and/or exhaust valves in several types of engines.

I claim:

1. In a rocker, a member adapted to be pivotally mounted, means mounted on and adjustable transversely of the member adapted to contact with a valve stem or the like, and a member having a beveled surface adapted to contact with the means to adjust it and maintain it in adjusted position during pivotal movement of the first member.

2. In a rocker. a member adapted to be pivotally mounted and having a bore therein, a member adjustably mounted in said bore and adapted to contact with a valve stem or the like, and means whereby the second member may be adjusted and maintained in adjusted position during pivotal movement of the first member.

3. In a rocker, a member having a bore therein and a second bore extending transversely of and intersecting the first bore, a member adjustabl mounted in one of the bores, and a mem r movable in the other a of said bores to adjust the second member.

4. In a rocker, a member having a longitudinal bore therein and a bore extending transversely of and intersecting the first bore,

a member adjustably mounted in the second 19 bore and having a portion adapted to contact with a valve stem or the like, and a member movable in the first bore to adjust the second member.

5. In a rocker, a member having a longi tudinal bore therein and a bore extending transversely of and intersecting the first bore, a member slidably adjustable in the second bore and extending into the first bore, a member slidable in the first bore and having a 20 beveled surface adjacent its inner end in contact with the second member, and a screw threaded in the outer end of the first bore and contacting with the outer end of the third member.

2 6. The invention claimed in claim 5 plus means to urge the second member against the beveled surface of the third member and means to urge the third member against the screw.

7. In power or motion transmitting mechanism, which includes a pair of movable power or mot-ion transmitting elements, a member carried by one of the elements and slidable toward and away from the other element, means adapted to urge the member away from the other element, means for moving the member toward the other element against the resistance of the first-mentioned means, means for urging the second-mew 4 tioned means away from the member, and means for maintaining the second-mentioned means in adjusted position during movement of the elements.

8. In valve operating mechanism, a rocker,

a slidably mounted member having an' inclined surface which is located on the rocker and is adapted to contact a valve stem or the like, and resilient means tending to move the member with respect to the rocker.

In testimony whereof I aflix my signature.

ROBERT R. HUTCHISON. 

